Method and apparatus for recovering zinc spatter



Aug. 14, 1956 w. s. PEARSON 2,758,944

METHOD AND APPARATUS FOR RECOVERING ZINC SPATTER Filed Feb. 9, 1951 William 8. Pearson 277 77426411 %m l /w zwig;

iiait dsw Perm O 2,758,944 METHOD AND APPARATUS FOR RECOVERTNG ZINC 'SPATTER William S. Pearson, Baltimore, Md., assignor, by mesne assignments, to C. 'C. Corporation, a corporation of Maryland Application February 9, 1951, Serial No. 210,225

1 Claim. (Cl. 117-102) The present invention relates to the recovery of zinc spatter in the removal of excess galvanizing zinc from freshly galvanized conduit or pipe.

In removing excess galvanizing material or spelter from freshly galvanized pipe, the excess material is blown while still in a fluid state from the surfaces of the pipe. As a result, the excess zinc leaves the pipe as droplets or spatter which gathers as uneven masses on the surface of an enclosure or guard or drops to a collecting surface as discrete blobs or particles. As a result of the large aggregate areas of the spatter thus exposed to atmosphere at great deal of oxidation takes place. Hence, when the spatter is returned to the zinc pot an undesirable amount of combustion occurs which destroys the galvanizing value of substantial quantities of the zinc by converting the same to ash.

A principal object of the present invention is to recover zinc spatter in such a manner that oxidation is greatly minimized so that the spatter can be returned to a zinc pot and retnelted for maximum pure metal yield for galvanizing purposes.

Another object of the invention is to provide a method of and means for recovering zinc spatter in such a manner as to substantially avoid burning of the zinc upon return to and remelting in a zinc pot.

A further object of the invention is to recover zinc spatter in an efiicient, labor-saving and economieal manner.

Still another object of the invention is to provide improved means for automatically recovering zinc spatter in such away that handling of the recovered Zinc is reduced to a minimum.

Yet another object of the invention is to accumulate and combine the discrete solidified particles of zinc spatter into relatively large, compact masses which will minimize oxidation and facilitate handling and eflicient re-melting of the zinc.

Other objects, features and advantages of the present invention will be readily apparent from the following detailed description of a preferred embodiment thereof taken in conjunction with the accompanying drawing, in which:

Figure l is a schematic and diagrammatic view of zinc spatter recovery apparatus embodying features of the present invention; and

Figure 2 is a vertical sectional fragmentary detail view taken substantially on the line 11-11 of Fig. l.

The present invention is especially suitable for use with apparatus for removing excess galvanizing metal or spelter from a freshly galvanized conduit or pipe 5, successive sections of which are removed from a zinc pot 6 and while in a heated condition and maintaining the galvanizing material in a fluid state are subjected to a fluid swabbing process by which the excess galvanizing material is blown from the surfaces of the pipe sections.

Apparatus for removing the excess galvanizing metal from the successive pipe sections may comprise a suitable framework 7 supporting an overhead conveyor systern including a first set of magnetic conveyor rolls 8, only Patented Aug. 14, 1956 one of which is shown in Fig. 1, to which the successive heated, freshly galvanized pipe sections, as removed from the zinc pot 6, are delivered and impelled endwise in an upwardly and forwardly inclined direction through a spatter chamber defined by a housing 9. This housing may be in the form of a cabinet including spaced verti cal walls 10 and 11 provided, respectively, with an entry opening 12 and an exit opening 13 properly aligned to afford continuous passage for each of the pipe sections 5 impelled onward by the overhead conveyor rolls 8.

Immediately outside the exit opening 13, the pipe section 5 is subjected to external swabbing by passing through a ring-type swab 14 from which is directed a circular series of streams or jets 15 of swabbing fluid such as superheated steam which converge through the exit opening 13 and wipingly impinge the external surface of the freshly galvanized pipe to drive excess spelter therefrom into the spatter chamber.

Immediately beyond the external swab 14, the pipe I section 5 is engaged by conveying means including a set of pinch rolls 17 which cooperate with additional forward conveying means (not shown) to move the conduit section onward until the trailing end portion of the pipe section has moved substantially through the spatter chamber and close to the inner side of the side wall 11. Thereupon, and before the trailing end of the pipe section has left the spatter chamber, the conduit section is halted and an internal swabbing blast of swabbing fluid such as superheated steam is directed down the inside of pipe section to drive excess galvanizing metal from the interior of the pipe. By reason of the pressure and velocity of the internal swabbing fluid, the excess galvanizing metal is ejected from the trailing end of the pipe section with substantial, virtually explosive force.

In order to avoid propulsion through the entry opening 12 of the excess zinc driven from the interior of the pipe section, a removable baflle 18 is interposed between the end of the pipe section and the entry opening 12 before the internal swabbing expulsion occurs. This baffle may be a flexible plate mounted within the housing 9 adjacent to the side wall 11 on a fixed attachment member or bracket 19 relative to which the plate is flexible. Flexing of the plate into and out of spelter intercepting relation is effected by means of an arm 20 motivated by suitable operating apparatus 21 which may be mounted on top of the housing.

As the excess zinc is swabbed from the pipe section 5 into the spatter chamber, the less vigorously propelled spatter drops toward the bottom of the spatter chamber while the more vigorously propelled spatter impinges the bafiie member 18 and to a substantial extent solidifies thereon. However, as the battle member 18 is flexed into and out of position, the solidified spatter is dislodged therefrom and drops toward the bottom of the chamber. It will be appreciated that the resulting deposit of spatter, in the absence of any compacting or agglomerating means will be in the form of discrete particles and masses of various sizes alfording, in the aggregate, great areas exposed to atmosphere and thus oxidation. Moreover, large numbers of voids and air pockets will be present in the accumulation of solidified spatter, especially when considered as an accumulation. It has been the practice to shovel the accumulation of solidified spatter back into the zinc pot for remelting. By reason of the large amount of oxygen present the high temperatures prevailing in the zinc pot have caused substantial combustion of the zinc resulting in a large amount of zinc ash and thus loss of zinc for galvanizing purposes.

According to the present invention the discrete solidified particles or masses of zinc spatter are compressed into a block of as solid a character as practicable, and as soon after solidification of the spatter as feasible, whereby oxidization is minimized and air pockets or voids are reduced to a minimum or eliminated and the resulting block of zinc can be conveniently handled for return into the zinc pot where in whole or at least to a major'extent the block will sink into the molten zinc and remelt with elimination of or at least substantial elimination of burning of the zinc.

The present process is carried out by agglomerating the solidified spatter in the lower portion of the spatter chamber. For this purpose, the lower portion of the chamber is provided with a hopper structure which may comprise a diagonal downwardly directed lower hopper wall 22 (Fig. 2) leading to a lower trough-like collector 23. In a convenient form, the collector 23 comprises a spatter chamber contained portion of a compactor tube within which is reciprocably disposed a ram 24. The compactor tube section within the spatter chamber has an upper opening 25 into which solidified spatter drops and is deflected by the hopper wall 22.

The ram 24 is guided by a portion of the receiver and compactor tube extending beyond one end of the receiver opening 25 and is arranged to move inwardly longitudinally of the receiver tube to drive the accumulated solidified spatter into a substantial portion of the receiver and compactor tube extending beyond the opposite end of the receiver opening 25 and providing a compactor cham ber housing 27. This housing provides a discharge opening at its distal end which is normally closed by an anvil block 28 against which the ram 24 drives the solidified zinc spatter for compacting the same. Suitable buttress structure 29 is provided behind the anvil block 28.

Suitable means are provided for driving the ram periodically in compacting and return strokes. To this end the outer end of the ram 24 may be provided with a piston 30 disposed within a cylinder 31 for pressure fluid actuation, either pneumatic or hydraulic. Pressure fluid is directed alternately into the opposite ends of the cylinder 31 for motivating the piston 30 and thereby the ram 24, through a pressure fluid supply duct system 32 including a control valve 33 operable by means such as an electrical relay or solenoid operator 34 under the control of an electrical switch 35 which may be operated in any appropriate manner selectively or automatically as desired. Through this arrangement, the ram 24 is reciprocated in compacting and return strokes to compact the solidified zinc spatter in the compacting chamber 27 progressively as the spatter is formed and before the spatter has been exposed for any appreciable length of time to the oxidizing influences of the atmosphere.

When the compacted mass of agglomerated zinc particles has reached a size wherein the compactor chamber 27 is substantially filled, the anvil block 28 is withdrawn from its blocking relation to the exit opening from the compacting chamber 27 and the ram 24 then acts to expell the compacted block from the compactor chamber end of the compactor tube. For this purpose, the anvil block 28 is preferably carried by a piston rod 36 having thereon a piston 37 whimh is reciprocably disposed within a cylinder 38 so that the piston 37 and thereby the piston rod 36 and the anvil 28 can be reciprocated by means of pressure fluid, either pneumatic or hydraulic, supplied from suitable source through a conduit system 39 and controlled by a control valve 40 arranged to be actuated by means such as an electrical relay or solenoid operator 41. Operation of the operator 41 may be efiected in coordination with compactor ram by the provision of pressure-sensitive switch means 42 communicating with the cylinder 31 so that when predetermined resistance pressure develops within the cylinder 31 during a compacting stroke of the ram 24, indicating that a block of sufiicient size of compacted zinc spatter has developed, an electrical circuit will be energized for activating the operator 41 to efiect withdrawal of the anvil 28 so that the compacted block can be ejected by the ram 24. As shown in dot-dash outline in Fig. l, the ram 24 is of sufficient length to extend to the exit end of the compactor chamber for this purpose. When the ram has completed the block ejection stroke, the anvil 28 is returned into the compacting position with respect to the compactor chamber 27 and a new compacting cycle begins. In such cycle the ram 24 moves from the end of the receiver opening 25 remote from the compactor chamber 27 toward and into the compactor chamber and in reverse until a block of compacted zinc spatter has been compacted in the compactor chamber 27.

Since there may be a tendency of the dropping zinc spatter to adhere in part on the hopper wall 22 or to bridge over the receiver opening 25, a scraper and pusher 43 may be provided for clearing the spatter from the hopper wall 22 and driving it into the receiver 23 where the ram 24 can act on the solidified spatter. The pusher 43 may be actuated in any appropriate manner either manually or by some mechanical means if desired.

It will be understood that modifications and variations may be effected without departing from the scope of the novel concepts of the present invention.

I claim as my invention:

In a method of recovering zinc spatter from freshly galvanized pipe sections as they come from the zinc pot, the steps of blowing excess zinc from successive sections into an enclosed spatter chamber having predetermined atmospheric conditions therein, allowing .the zinc to solidify in the chamber, collecting the particles of zinc spatter within the chamber progressively as the solidifiedv spatter is formed, and before the spatter has been exposed for any appreciable length of time to the influences of the atmosphere within the chamber, compacting the particles into an aggregative substantially void-free mass, said compacting continuing progressively as successive pipe sections are blown free of excess zinc until a block of predetermined size has been formed for convenient handling and return for remelting in the zinc pot.

References Cited in the file of this patent UNITED STATES PATENTS 1,193,680 Fulton Aug. 8, 1916 1,260,312 Brown Mar. 26, 1918 2,029,984 Buttfield Feb. 4, 1936 2,259,465 Hardy Oct. 21, 1941 2,302,980 Stern Nov. 24, 1942 

